Allegations of cheating were made throughout the 1994 Formula One World Championship. Several Formula One teams were involved, with the main allegations surrounding Benetton Formula. Initially, Benetton was alleged to have been using illegal traction control software to their advantage in races; however, this could not be sufficiently proven by the FIA and was only confirmed in 2015 when Willem Toet, one of Benetton's engineers that season, wrote an article on his Linkedin account describing how the team developed a traction control system using spark cutting. A refuelling fire on Jos Verstappen's Benetton car at the 1994 German Grand Prix led to renewed allegations and an investigation by Intertechnique at Benetton's team factory. Following the investigation, the FIA revealed Benetton had been using a fuel valve without a fuel filter, which allowed fuel into the car 12.5% faster than a legal fuel valve. Renewed allegations led to rumours of Michael Schumacher quitting the team. Schumacher would end up staying with Benetton for the 1995 Formula One season, also winning the Drivers' World Championship that season, before joining Ferrari for the 1996 Formula One season where he would stay until the 2006 Formula One season, winning five additional Drivers' titles in the process.
Following the 1994 San Marino Grand Prix, the Benetton, Ferrari, and McLaren teams were investigated on suspicion of breaking the FIA-imposed ban on electronic aids. Benetton and McLaren initially refused to hand over their source code for investigation. When they did so, the FIA discovered hidden functionality in both teams' software but no evidence that it had been used in a race. Both teams were fined $100,000 for their initial refusal to cooperate. The McLaren software, which was a gearbox program that allowed automatic shifts, was deemed legal. By contrast, the Benetton software was deemed to be a form of launch control that would have allowed Schumacher to make perfect starts, which was explicitly outlawed by the regulations; Benetton and Willem Toet, a Formula One aerodynamicist for over thirty years who worked at Benetton until 1994, stated that traction control was legally achieved through rotational inertia. There was no evidence to suggest the software was used.
Background The technical regulations for the 1994 Formula One season were announced at the 1993 Canadian Grand Prix. One of the major announcements was that electronic aids were to be banned, which included power brakes and traction control systems. Also banned for the 1994 season was the use of anti-lock braking systems (ABS) and active suspension. This was done as there were fears that electronic aid systems were levelling the field up, putting more emphasis on the car rather than driver talent. Some spoke out against traction control, including Ayrton Senna, who said he preferred to have more control of the car instead of having the computers drive it for him. Ironically, Senna would later say that he believed there would be a lot of accidents during the 1994 season since no attempts were being made to slow the cars down while taking said driver aids away. Max Mosley, the president of Formula One's governing body, the FIA, spoke in favour of banning traction control, saying that the systems "could be extremely dangerous and unpredictable".
Around the same time as the announcement regarding the technical regulations for the 1994 season, many in the sport were questioning the legality of active suspensions, which was a key factor in their ban for 1994. Some in the paddock regarded the decision as an attempt to restrict Williams, as the team held a strong advantage with its active suspension and other driver aids. The unraced concept of continuously variable transmission (CVT) was also banned; it was well known that Williams had spent several years developing and testing such a system, which threatened to further increase their cars' advantage if introduced.
Behind the scenes at Williams, they considered the timing of the announcement as "regrettable", with some questioning if Nigel Mansell's 1992 Formula One World Championship victory would still be regarded as valid. Also introduced for the 1994 season was refuelling during races for the first time since . As a result, all team personnel working on the car during pit stops had to wear fire-protective clothing as a safety precaution. The FIA changed the rules to increase interest in the sport partially due to declining television ratings from the season compared to the season. It was also suggested the rule changes could benefit the Ferrari team, as the outfit had struggled with the introduction of its driver aids, and stood to gain from the re-introduction of refuelling due to its V12 engine configuration, which was less fuel-efficient than the V10s and V8s built by their rivals.
Initial allegations Cheating allegations were made at the 1994 Brazilian Grand Prix, the first round of the season. On lap 21 of the race, Senna in the Williams who was leading the race, made a pit stop, with Michael Schumacher in the Benetton close behind. The Benetton pitcrew made a very quick stop for Schumacher, getting him out in front of Senna to lead the race. Schumacher went on to win the Grand Prix after Senna spun out of the race. This sparked speculation that Benetton was using a system to make quicker pit stops than their rivals.
During the weekend of the 1994 Pacific Grand Prix, Ferrari test driver Nicola Larini (who had replaced Jean Alesi for the early part of the season) leaked to the Italian media that he had used traction control during the practice session for the race. Ferrari and Larini later denied the claims to the worldwide press. The leak by Larini further raised suspicions about teams using illegal driver aids to help them in races. Senna retired on the first lap of the race after a collision with McLaren driver Mika Häkkinen. Instead of going back to the Williams pit area, Senna opted to stand and watch the cars complete the race to see if he could hear any noises that suggested traction control was being used illegally in the other cars. Senna returned to the Williams pit area after the race suspicious that the Benetton car was illegal.
Rule changes At the 1994 San Marino Grand Prix, both Senna and Roland Ratzenberger suffered fatal accidents. After the race weekend, the FIA asked the teams that finished first, second and third in the race (Benetton, Ferrari, and McLaren, respectively) to provide copies of their engine management system's source code to see if a traction control system was being stored. Ferrari supplied the code immediately, while McLaren and Benetton only handed over the code after the FIA's deadline, for which they were fined $100,000. Prior to this, the FIA had agreed to view a demonstration of the Benetton system at Cosworth's engine facility, as Cosworth considered the software to be their property and refused to give Benetton permission to provide it to the FIA.
Several technical rule changes were announced by the FIA at the 1994 Monaco Grand Prix to help improve the safety of the cars. Downforce on the cars was reduced with the diffuser restricted to help reduce the amount of grip available. In between the Monaco and Spanish Grands Prix, the teams tried out the revised cars in test sessions throughout the week. Several teams experienced problems with their revised cars; Ligier suffered two cracked wing mountings, while Williams noted a cracked mounting during testing at the Jerez Circuit. The biggest incident was that of Pedro Lamy in a Lotus car at the Silverstone Circuit. While approaching the Bridge corner on the circuit, the rear wing on the Lotus detached itself leading to a sudden loss of downforce. The Lotus cartwheeled off the circuit at , flying through a protective fence, landing in a spectator access tunnel. Lamy was hospitalised as a result of the accident. In the week leading up to the 1994 Spanish Grand Prix, Benetton team boss Flavio Briatore criticised the FIA, accusing the president Max Mosley of making "ill-considered, snap decisions" and that some of the components on the Benetton car may not have been subjected to quality control checks. In a letter sent to Mosley on May 25, Briatore also said:
The Benetton team, along with Williams, McLaren, Lotus, Pacific, Simtek, Jordan, Footwork Arrows, and Ligier debated the issue in the Williams motorhome to discuss the technical regulations. More changes came into force for the 1994 Canadian Grand Prix on 12 June and the 1994 German Grand Prix on 31 July, with the introductions of pump fuel (more closely related to commercially available fuel, slightly reducing horsepower, and engine performance) and the plank (a piece of wood running along the underside of the chassis that is monitored for excessive wear, increasing ride height and thus decreasing grip).
Renewed allegations Allegations of cheating reignited at the 1994 French Grand Prix when, starting from third on the grid, Schumacher overtook both of the Williams drivers, Damon Hill and Nigel Mansell, leading into the first corner of the race. This again raised suspicions that Benetton were using traction control. There were also incidents involving other teams, notably Ferrari and McLaren. While commentating on the race for Eurosport with John Watson and Allard Kalff, Williams driver David Coulthard, who was replaced by Mansell for the race, stated that Schumacher's start reminded him of the type of starts from the 1993 season when traction control was legal.
In July 1994, the FIA announced that it had analyzed Benetton's black boxes from Imola and found a launch control system in the software. It included what appeared to be a hidden trigger system which was highly suspicious. During the investigation several discrepancies regarding the capabilities of the system were found, some even surprising Benetton. The investigation showed it could be switched on by a laptop PC, that Benetton's menu did not reveal launch control as an option, and that it was an option but it was not visible (Option 13). Although the team admitted the existence of the code, it argued it was redundant and could not be activated by Schumacher. Benetton further stated that the driver's aid was only used in testing and that it was elaborate in order to prevent it being switched on accidentally, and that the launch control could only be started by recompilation of the source code. The rules at the time only prevented the use of traction control, not the existence of software that might be used to implement it. As the FIA had no proof it was being used, no action was taken. The FIA ultimately issued a statement concerning the investigation of the alleged use of an automatic start system by Benetton at Imola. The conclusion was that "the best evidence is that Benetton Formula Ltd was not using 'launch control' at the 1994 San Marino Grand Prix". Had the evidence proved otherwise, Benetton faced being excluded from the World Championships.
Willem Toet, the Head of Aerodynamics for Benetton in 1994, stated that traction control was legally achieved through rotational inertia. He also expressed his belief it was Schumacher's technique that Senna initially mistook for illegal traction control during the Pacific Grand Prix. He suggested that Schumacher's technique of braking with his left foot could have fooled Senna into thinking the Benetton was illegal. This opinion was not widely accepted as the LFB technique had been used in Formula One since the early 1970s. In fact, Senna's own teammate Gerhard Berger was known to have used left foot braking in 1992 when he had been Senna's teammate.